The long-anticipated move — Trump is the first first lady in modern history to delay her arrival — is expected to lend some degree of normalcy to a presidency defined by its abnormality in substance and style.

“Her presence is not going to stop any investigations, but at a time when this particular presidency needs an air of stability, it might lend that,” said Katherine Jellison, a history professor at Ohio University who specializes in first lady studies. “The move helps to give the impression that the president is currently in a stable, solid marriage and that his home life is under control.”